Worm gearing



A. B. CRICHTON, JR.. ETAL 2,713,799

July 26, 1955 WORM GEARING 2 Sheets-Sheet 1 Filed Sept. 20, 1950 July26, 1955 A. B. CRICHTON, JR.. ET AL ,7

' WORM GEARING Filed Sept. 20, 1950 2 Sheets-Sheet 2 United StatesPatent WORM GEARING Andrew B. Crichton, Jr., Johnstown, Pa., and Carl G.Wennerstrom, Chicago, 11]., assignors to The Crichton Company,Johnstown, Pa., a corporation of Delaware Application September 20,1950, Serial No. 185,884 5 Claims. (Cl. 74-425) The present inventionrelates to a power or speed increase take-off unit or assembly adaptedbut not necessarily intended for removable interposition between a drillhead or other device and a short wall coal cutter which drives andsupports it generally like the speed increase take-01f unit or assemblydisclosed as part of our pending application for patent, Ser. No.21,893, filed April 19, 1948, entitled Power Take-Off System andApparatus, now matured into Patent No. 2,645,944, issued July 21, 1953.

While it is aimed to provide such a structure which attains the ends andpossesses the advantages set forth in said application, it isparticularly aimed to provide a novel construction especially whereinthe power and takeoff shafts are disposed at a right-angle to eachother, one embodying a novel safety clutch means adapted toautomatically yield or slip upon encountering predetermined resistance,a construction wherein power may be taken from the take-01f shaft at aplurality of locations, and a construction wherein such latter shaft inparticular and all parts as a whole are embodied in an exceedinglysturdy, compact and durable unit.

Various additional objects and advantages will be pointed outhereinafter, and otherwise become apparent from a consideration of thedescription following, taken in connection with the accompanyingdrawings illustrating an operative embodiment.

In said drawings:

Fig. 1 is a side elevation of the improved unit shown attached to afragment of a short wall coal cutter;

Fig. 2 is a view of the parts of Fig. 1 primarily in v 2,713,799 IcePatented July 26, 1955 nism to be later specifically described, theinput power is used to drive or to operate an output shaft 0 disposed ata right-angle thereto.

Said power-receiving main shaft is stepped and journalled in ballbearing devicesl and 17 suitably seated in enlargements 18 and 19 of thecasing section 11 and wall 13. A seal 20, also mounted by enlargements18, surrounds shaft 15. On one side of bearing device 17 a washer 21 isapplied to shaft 15, while on the other side a retaining snap ring 22engages a groove of the shaft.

Loose or journalled on main shaft 15 is a worm wheel 23 to which isintegrally welded or otherwise secured, a clutch head in the form of aplate or flange 24, with which coacts a clutch head in the form of aplate or flange 25 keyed or otherwise rigidly connected to main shaft 15as at 26. One of said plates or flanges 25 and 26, for instance theformer in recesses 27, houses one or more clutch pins 28 having conicalheads 29 normally engaging conical recesses 30 of the plate or flange24, and so urged by expansive coil-springs 31 abutting plate 25 and theheads 29 and surrounding shanks 32 of said pins guided in adjacentopenings 33 of plate 25.

Above power-receiving main shaft 15 and at a rightangle thereto is anintermediate shaft 34, parallel to output shaft 0, embodying a worm 35enmeshed with the teeth of worm wheel 23. Said intermediate shaft 34 andparts directly associated therewith are insertible through the openingof the casing normally covered by plate 12. One end of such shaft 34(Fig. 3) is journaled at 36 in the adjacent wall of the casing and at alocation spaced therefrom; such shaft is journalled in a ball bearingdevice 38 mounted in an internal web or wall 39 of easing section 11.Said ball bearing device 38 at one side abuts a flange 40 on said shaft34 and its other side is overlapped by a ring nut 41 screw-threaded at42 to plan, but partly broken away and in section to disclose details;

Fig. 3 is a vertical sectional view taken on the plane of lines 33applied to Figs. 1 and 4; and

Fig. 4 is a vertical sectional view taken on the line 4-4 applied toFig. 3.

Referring specifically to the drawings, wherein like referencecharacters designate like or similar parts, the unit or assemblyincludes a suitable case 10 preferably consisting of a main section 11,an end plate 12, and a side plate or wall 13, all suitably and separablysecured together. Extending into said casing, through its rear wall is apower receiving main shaft 15 adapted to be rotated or driven by aninput or power take-01f shaft to which it is coupled or fastened in anysuitable manner according to the particular machine used as a source ofpower.

The instant construction is especially useful though not restricted tosuch employment, like the take-oft" assembly or unit disclosed in ourpending application, Ser. No. 21,893, aforesaid, and thus the shaft 15is adapted to be driven from a short wall coal cutter fragmentarilysuggested at C, and may be part of or an extension of a take-off shaftor other driven part thereof. On the other hand, said input shaft 15 maybe a shaft driven from and separably attached to the take-off shaft ofthe short wall coal cutter C, such as the shaft illustrated at 28 insaid application, Ser. No. 21,893. Through the mechasuch shaft. A flange43 and removable ring 44 specifically position bearing device 38 in saidweb 39.

Keyed on intermediate shaft 34 at 45 between plate 12 and web 39 is apinion or gear wheel 46, which is enmeshed with a pinion or gear wheel47 fast on the previously mentioned output shaft 0.

Power is selectively taken off either end of output shaft 0 as suggestedby the flexible shafting dotted at 48 and may be used for operating adrill head in coal mining as disclosed in our previously mentionedpending application, but at the same time may equally well be used forgeneral purposes, such as to operate one or more faces or cross-cutconveyors, portable rock dusters, hoists, saws and the like. Saidflexible shafting 48 extends into and around sockets 49 and 5t) and issuitably coupled to blades 51 or otherwise to shaft 0. Socket 49 isfixed to plate 12 and socket is fixed to casing section 11. Reduced ends52 and 53 of said shaft 34 are journalled in webs 54 of said sockets 49and 50. Needle bearing devices 55 carried by socket 550 and web 39directly journal said shaft 0. Washers 56, 57 and 58 position saidpinion 47 on the reduced portion 52 in contact with shoulder 59.

Any suitable means may be provided to prevent rota tion of the instantunit as a Whole with shaft 15. At opposite ends of easing 1t), as on theclosed end wall of section 11 and end plate 12, are bosses 60 whichslidably mounted manually operable clutch bolts 61 urge toward sockets49 and 50, respectively, by coacting' expansive springs 62 to separablyoverlap a shoulder 63 on the flexible shafting 48.

Reverting to springs 31, they are adapted to yield at a predetermineddegree of tension, as a safety measure, so that the drill-head and drillor the like coupled to flexible shafting 48 in encountering undueresistance cannot twist the arms and body of the operator when using thesame.

In use, the power-receiving main or input shaft 15 being driven by theshort wall coal cutter C or otherwise, will in turn rotate flange orplate 27 rigid thereon and through the coupling pins 28 normally rotateflange 24 and worm-wheel 23 unitarily therewith. Since worm- Wheel 23enmeshes with worm 35, it drives intermediate gear-shaft 34, gears 46and 47, output shaft and flexible shafting 48, and accordingly thedrill-head or equivalent. Since springs 31 are of a predetermined knowndegree of tension, clutch pins 38 will automatically yield upon thedrill head or equivalent encountering undue resistance as a safetymeasure as previously explained. In such event, the undue torque causesthe coacting conical surfaces of the heads 29 and walls of recesses 30to slide the clutch pins 28 out of recesses 30, overcoming the action ofspring 31, and thus unclutching the heads 24 and 25 so that shaft 15will rotate freely within worm wheel 23 and not drive it.

Various changes may be resorted to, provided they fall within the spiritand scope of the invention as defined by the appended claims.

What is claimed is:

l. A power take-01f assembly comprising a casing, a power input shaftjournaled therein, a gear on the latter and driven thereby, bearings forsaid shaft between which said gear is disposed, a second shaft, saidsecond shaft having its axis at a different elevation from said inputshaft and disposed approximately at right-angles thereto, a gearenmeshed with said first gear and disposed in driving relation to saidsecond shaft, said casing having an opening at one wall thereof, a webinwardly of said wall, said second shaft being journaled in said web andin a wall of said casing in spaced relation to the web, a plate closingsaid opening, an output shaft journaled in said web, gearing between thesecond-mentioned and output shafts disposed in the casing between saidweb and said plate, and a socket mounted in one end of said casing andin which said output shaft is journaled, and adjacent which it isadapted for attachment to the element to be driven.

2. A power take-off assembly comprising a casing, a power input shaftjournaled therein, a gear on the latter and driven thereby, bearings forsaid shaft between which said gear is disposed, a second shaft, saidsecond shaft having its axis at a different elevation from said inputshaft and disposed approximately at right-angles thereto, a gearenmeshed with said first gear and disposed in driving relation to saidsecond shaft, said casing having an opening at one wall thereof, a webinwardly of said wall, said second shaft being journaled in said web andin a wall of said casing in spaced relation to the web, a plate closingsaid opening, an output shaft journaled in said web, gearing between thesecond-mentioned and output shafts disposed in the casing between saidweb and said plate, and aligned sockets, one mounted in said plate andthe other in the wall of the casing opposite thereto, said socketshaving webs in which said ouput shaft is journaled.

3. A power take-off assembly comprising a casing, a power input shaftjournaled therein, a worm-gear on the latter and driven thereby,bearings for said shaft between which said gear is disposed, a secondshaft, said second shaft having its axis at a different elevation fromsaid input shaft and disposed approximately at right-angles thereto,said second shaft having a worm enmeshed with said worm-gear, bearingsfor said second shaft between which said worm is disposed, said casinghaving an opening at one wall thereof and a web inwardly of said wall,said second shaft being journaled in said web and in a wall of saidcasing in spaced relation to the web, a plate closing said opening, anoutput shaft journaled in said web, and a gearing between thesecond-mentioned and output shafts disposed in the casing between saidweb and said plate.

4. A power take-off assembly comprising a casing, anti-friction devicesjournaled in said casing in spaced relation, a power input shaftjournaled in said casing and extending exteriorly thereof and attachableto a source of power, a worm gear through which said shaft extends, saidworm gear being disposed between said bearing devices, a shaft disposedabove and at a right-angle to the first mentioned shaft having a wormenmeshed with said worm gear, said casing having an opening at a wallthereof, and a web inwardly of said wall, said secondmentioned shaftbeing journaled in said web, a plate closing said opening, an outputshaft journaled in said web in parallelism to the first-mentioned shaft,and gearing between the second-mentioned and output shafts disposed inthe casing between said web and said plate.

5. A power take-off assembly according to claim 4 having aligned socketsmounted one in said plate and one in the wall of the casing oppositethereto, said sockets having webs in which said output shaft isjournaled.

References Cited in the file of this patent UNITED STATES PATENTS795,360 McCornack July 25, 1905 865,486 Gannon Sept. 10, 1907 1,449,572Zuhars et al Mar. 27, 1923 1,493,188 Campbell May 6, 1924 1,651,822Johnston Dec. 6, 1927 1,914,503 Holmes June 20, 1933 2,156,739 SchmitterMay 2, 1939 2,426,351 Jeffrey Aug. 26, 1947 2,544,809 Stanley Mar. 13,1951 FOREIGN PATENTS 603,435 Germany Sept. 29, 1934

